Wall-reinforcing prostheses, for example prostheses for reinforcing the abdominal wall, are widely used in the surgical field. These prostheses are intended to treat hernias by temporarily or permanently filling a tissue defect. These prostheses are generally made of biocompatible prosthetic fabric, in particular prosthetic knits, and can have a number of shapes, for example rectangular, circular or oval, depending on the anatomical structure to which they are to be fitted.
In a view of reducing the foreign material implanted into the body of a patient, it is desired to produce lightweight knits, intended to be used as wall reinforcing prostheses. In addition, for facilitating the work of the surgeon at the time he puts the prosthesis in place at the implantation site, it is further desired that the prosthetic knit show a good transparency. Moreover, the wall reinforcing prosthesis should also favor a good tissue ingrowth. In this view, it is desired that the knit used for wall reinforcing prostheses show a plurality of pores, and preferably large pores.
Lightweight porous knits usable in the manufacture of wall reinforcing prostheses already exist. Nevertheless, they sometimes show poor mechanical strength. Indeed, the knit is generally pliant and soft in order to conform to the abdominal wall and flex with movement of the abdominal wall once implanted. The knit may be held in place by suturing, stapling, or tacking the knit to surrounding biological tissue. In particular, existing lightweight porous knits may show a poor resistance to fracture when they are sutured or tacked to the surrounding biological tissue.
In addition, the performance of the abdominal wall hernia repair using a prosthetic knit fixed on the abdominal wall depends in part upon the shear forces experienced at the knit fixation points. These shear forces may be quite high as a result of high intra-abdominal pressure.
Too high shear forces at knit fixation points, once the knit or prosthesis is implanted and has been fixed for example by sutures at the abdominal wall, may lead to abdominal wall repair recurrences and/or generate pain for the patient. The distribution of shear forces at fixation points is important to assess the safety and the efficacy of the abdominal wall repair.